It's a classic image: elephants lumbering trunk to tail. But is this docility born of positive reinforcement—or fear of being beaten? Keith Meyers/The New York Times/Redux

It was a drizzly winter day, and inside the Jacksonville Coliseum, Kenny, a three-year-old Asian elephant, was supposed to perform his usual adorable tricks in The Greatest Show on Earth: identifying the first letter of the alphabet by kicking a beach ball marked with an "A," twirling in a tight circle, perching daintily atop a tub, and, at the end of his act, waving farewell to the audience with a handkerchief grasped in his trunk.

But Kenny was clearly sick. Elephants are highly intelligent creatures that develop at a similar rate as humans. In the wild, Kenny would still be at his mother's side, just beginning to wean. In captivity, he was a voracious consumer of water and hay but for the past day or so had showed little interest in either. He seemed listless. Worried attendants in the tent where the elephants were chained between shows twice alerted a circus veterinary technician.

Under federal regulations, sick elephants must get prompt medical care and a veterinarian's okay before performing. Neither occurred, and at showtime Kenny trotted out to the center ring. He developed diarrhea during the morning show. During the afternoon performance, he began bleeding from his bottom and afterward struggled to stay on his feet. It was only then that Gary D. West, a circus veterinarian, arrived from St. Petersburg to examine the young elephant. West prescribed antibiotics and recommended that Kenny skip the evening show—in a later affidavit, he didn't stress concern for the elephant's health but rather that "he might pass some blood which might be seen by a spectator and cause speculation as to his well being."

West was overruled by Gunther Gebel-Williams, Ringling Bros. and Barnum & Bailey's legendary golden-haired animal tamer who'd retired from the ring to be vice president of animal care. So Kenny made his third appearance, although he was too weak to perform any stunts.

After the evening show, the bleeding continued. The elephant crew gave Kenny rehydration fluids and shackled him in his stall. Less than two hours later, a night attendant discovered his bloodied body on the concrete floor. The cause of death remains unclear.

Feld Entertainment, Ringling's corporate parent, did not announce Kenny's death to the public for nearly a week, until an employee tipped off animal rights activists. They demanded action from the Department of Agriculture, which licenses and inspects circuses under the Animal Welfare Act. Under intense public pressure, including a letter-writing campaign headlined by Kim Basinger, the USDA charged Feld Entertainment with two willful violations for making Kenny perform ill without prompt or adequate veterinary care.

More: Read court transcripts, vet records, and other primary sources from this investigation.

That was in 1998, and at the time it seemed like a turning point in the decades-long fight over circus elephants. For years, animal rights organizations had been releasing horrific undercover videos showing Ringling trainers abusing elephants, but USDA investigations never produced evidence that officials deemed strong enough to warrant action. Now there was a dead body—and a recent precedent. The agency had just fined the King Royal Circus, a small family operation, $200,000 for allowing an elephant to die in an overheated trailer of an untreated salmonella infection.

But after a few months, the USDA announced a settlement. Feld Entertainment would donate $20,000 to elephant causes. In return, the agency absolved the company of blame for Kenny's death and further declared, "Ringling Bros. has never been adjudged to have violated the [Animal Welfare Act]."

"If I were an elephant, I wouldn't want to be with Feld Entertainment," admitted a USDA official. "It's a tough life."

The USDA unwittingly opened a new chapter in the animal rights movement. Frustrated by the agency's inaction, advocates turned to the federal courts. This shift in strategy has not yet produced a judgment against Feld Entertainment, but it has unearthed an extraordinary trove of records that its lawyers and government regulators had taken great pains to ensure the public would never see; in one notable instance, documents came to light only after a judge threatened to put Feld executives in jail. They include dozens of videos and thousands of pages of investigation files, veterinary records, circus train logs, and courtroom testimony.

Feld Entertainment is a privately held corporation owned by Kenny's namesake, CEO Kenneth Feld, whose family bought Ringling for more than $8 million in 1967 and folded it into an entertainment empire that includes Ringling's three year-round touring circus troupes, as well as Disney On Ice, Disney Live, and Monster Jam. Together these shows play for more than 30 million people a year, with annual revenues estimated at between $500 million and $1 billion. But the four-ton behemoths are the biggest draw, generating more than $100 million annually in revenues, according to testimony by Feld executives.

It's hard not to be captivated. Elephants are smart, social creatures that communicate through a complex score of rumbles, trumpets, and gestures; they also have long memories and the capacity to celebrate, mourn, and empathize.

Feld Entertainment portrays its population of some 50 endangered Asian elephants as "pampered performers" who "are trained through positive reinforcement, a system of repetition and reward that encourages an animal to show off its innate athletic abilities." But a yearlong Mother Jones investigation shows that Ringling elephants spend most of their long lives either in chains or on trains, under constant threat of the bullhook, or ankus—the menacing tool used to control elephants. They are lame from balancing their 8,000-pound frames on tiny tubs and from being confined in cramped spaces, sometimes for days at a time. They are afflicted with tuberculosis and herpes, potentially deadly diseases rare in the wild and linked to captivity. Barack, a calf born on the eve of the president's inauguration, had to leave the tour in February for emergency treatment of herpes—the second time in a year. Since Kenny's death, 3 more of the 23 baby elephants born in Ringling's vaunted breeding program have died, all under disturbing circumstances that weren't fully revealed to the public.

But perhaps more disturbing still is the government's failure to act. Since Kenny's death, the USDA has conducted more than a dozen investigations of Feld Entertainment. Inspectors have found baby elephants injured and bound at Ringling's Center for Elephant Conservation in Florida. Whistleblowers have stepped forward with harrowing accounts of beatings. Activists have released even more videos of elephant abuse, and local humane authorities have documented wounds and lameness.

None of that has moved regulators to action.

Circus oversight rests with the animal care unit in the USDA's Animal and Plant Health Inspection Service. Officials there, as at Feld Entertainment, were not willing to be interviewed. So I called W. Ron DeHaven, who headed the animal care unit from 1996 until 2001 before ascending to lead all of APHIS from 2004 to 2007. (He is now executive vice president of the American Veterinary Medical Association.)

Ringling elephants spend most of their long lives either in chains or on trains, under constant threat of the bullhook, or ankus—the menacing tool used to control elephants.

During DeHaven's tenure at the USDA, a 2005 audit by the department's inspector general criticized the animal care unit for being too lenient on violators. The report singled out the Eastern region, which oversees Ringling's operations, for its failure "to take enforcement action against violators who compromised public safety or animal health."

With an annual budget of only $16 million and 111 employees to monitor nearly 9,000 animal entertainment, breeding, and research facilities, the agency didn't have the capacity to prosecute many cases, DeHaven explained. He acted on the egregious cases, he said, like King Royal. I asked what made that case worse than others. A dead elephant, he said, and a clear violation.

How was that different than Kenny? DeHaven said he didn't recall the particulars of that case. But, he added, "You don't take on an organization like Feld Entertainment without having strong evidence to support it."

That sentiment was echoed by Kenneth H. Vail, who for decades served as the USDA's lead legal counsel on animal welfare cases. We met at his red brick townhouse in northwest DC in July, just after his retirement. Thin-faced, with soft eyes and a quiet voice, he invited me in out of the 100-degree heat to talk for more than an hour. He said Feld Entertainment cases received special attention from him and other top department brass. "A case involving a multimillion-dollar company is significant," Vail said. "There's a political aspect to Feld cases. The company is a big target for animal rights groups." True, USDA investigators advocated action against Feld Entertainment on numerous occasions, but Vail said he never felt their evidence could withstand a legal challenge by the company. "There's no way to control an elephant without an ankus," and the Animal Welfare Act doesn't prohibit it, he explained. Maybe a time will come when bullhooks, chains, and "elephants getting paraded around doing unnatural things" is prohibited, he said, but until then, litigating abuse is difficult.

"If I were an elephant, I wouldn't want to be with Feld Entertainment," Vail conceded. "It's a tough life."

Save for modern sound and lighting systems, today's circus hasn't changed all that much from the spectacle created by P.T. Barnum, the corpulent showman who delighted audiences with midget Tom Thumb, faux mermaids, and soprano Jenny Lind (PDF).

Courtesy Library of CongressBy 1850, Barnum also had a traveling menagerie that featured an elephant or two. But he imagined an entire herd, so he dispatched agents to sail to Ceylon (now Sri Lanka), where they hired 160 "native assistants" to search the jungles. The most daring waited until an elephant napped against a tree. They would tickle a sensitive spot on the elephant's hind leg and, when it lifted its foot to shake off the nonexistent insect, slip a noose around its ankle. The expedition "killed large numbers of the huge beasts," Barnum wrote in an autobiography. But 11 live ones were hoisted into a ship's hold for the 12,000-mile voyage to New York City. One died en route and was dumped overboard. Barnum paraded the rest down Broadway harnessed to a chariot, and they became the featured attraction of a new traveling show, Barnum's Great Asiatic Caravan, Museum, and Menagerie.

The elephants drew rave reviews—"It is astonishing to think how docile these huge creatures are, when it is remembered that but a brief time since they were running wild in the jungle," a writer mused in Gleason's Pictorial Drawing Room Companion—and huge profits. Barnum's circus grew into ever more elaborate productions, with dangerous cats, prancing horses, legions of clowns, trapezes, high-wires, and three rings under a tent the size of a palace. Barnum joined James Anthony Bailey and then merged with the seven Ringling brothers to make "The Greatest Show on Earth." The conga line of elephants was the act that crowds most flocked to see.

This was the circus Irvin Feld envisioned when he acquired Ringling in 1967. Feld, born in 1918, got his first taste of circus life as a teenager, selling snake oil (literally) from a card table at carnivals. He became an innovative music promoter, recognizing early on that serious money could be made using sports arenas for concerts and promoting then-unknowns like Chubby Checker and The Everly Brothers. In 1956, when Ringling had lost both luster and financial footing, Feld persuaded Ringling's grandson to abandon the big top for sports arenas. After 10 years as the circus' booking agent, he and two partners bought it. John Ringling North cited "their dedication to maintain the concept, tradition, and artistic standards of the circus." Feld called it "the happiest moment of my life."

Feld immediately recruited German superstar Gunther Gebel-Williams, "the greatest wild animal trainer of all time," to help boost lagging ticket sales. Back then, Ringling had just one touring company, the Blue Unit. Feld added the Red Unit to showcase Gebel-Williams and his menagerie of some 20 elephants and 50 big cats. Svelte and handsome, Gebel-Williams would enter the ring bare-chested astride two galloping steeds, send tigers leaping through flames, lead a line of elephants through a tumbling act, cuddle up with panthers, and exit with a leopard draped around his neck—an image memorialized in a 1970s American Express commercial.

Feld seemed on his way to restoring The Greatest Show on Earth to the height of its glory. But outside the ring, times were changing. The movie Born Free, about a couple who raised an abandoned lion cub and then set it free in Kenya, won two Academy Awards the same year that Feld bought the circus. "Animal rights" had entered the popular lexicon. Congress expanded the Animal Welfare Act in 1970, charging the USDA with setting humane standards for treatment of warm-blooded animals by researchers, breeders, and exhibitors—including circuses. In 1973, Congress passed the Endangered Species Act, which barred "harm" or "harassment" of listed animals. Asian elephants made the endangered list several years later, and their import was banned under international conventions. Smaller than their African cousins and generally considered much easier to manage, Asian elephants had for decades comprised the vast majority of Ringling's stock. The listing effectively shut down the supply line.

By the time Irvin Feld died in 1984, leaving his son, Kenneth, to run the show, animal rights organizations were proliferating. Zoos began adopting an emerging animal management philosophy called "protected contact," which controls animals with physical barriers instead of sticks and chains. But this was of little use to the circus, where direct interaction between humans and wild beasts is the point. Feld Entertainment faced a conundrum: The audiences still wanted to see elephants—but they wanted to see them treated nicely.

Renowned Ringling Bros. trainer Gunther Gebel-Williams during his 1989 farewell tour Scott McKiernan/Zuma Press/NewscomSo the company poured tens of millions of dollars into PR campaigns that portrayed the elephants as willing performers, as well as legal firepower to keep regulators and activists at bay. Gebel-Williams got a makeover. A press release lauded his "animal training based on mutual respect and positive reinforcement" that "forever changed the standards of animal training." It's true that Gebel-Williams had an extraordinary rapport with the animals, but it's also true that he routinely whipped elephants and struck them with bullhooks. A few months after Kenny's death, Gebel-Williams was spotted whipping a baby elephant in the face outside a circus train in Mexico City.

Nonetheless, the sleight of hand worked. When Gebel-Williams died in 2001, the Sarasota Herald-Tribune's obituary noted that he had "substituted humane, positive reinforcement and reward for the fear and force upon which many animal trainers rely."

The biggest challenge for Feld Entertainment's "positive reinforcement" campaign was the ubiquitous bullhook or ankus. It's a malevolent-looking instrument, about three feet long, with a sharp, metal point-and-hook combination at one end. The point is for pushing. The hook, inserted in the mouth or at the top of the ear, is for pulling. Both are sharp enough to pierce elephant hide.

In Rudyard Kipling's 1894 classic, The Jungle Book, Mowgli finds an ankus and asks the panther Bagheera what it is used for:

"It was made by men to thrust into the heads of [elephants]," said Bagheera. "That thing has tasted the blood of many."

"But why do they thrust into the heads of elephants?"

"To teach them Man's Law. Having neither claws nor teeth, men make these things, and worse."

Feld Entertainment rebranded the ankus as a "guide." Handlers hid them in their sleeves or carried smaller, less menacing-looking models during the show. As Joan Galvin, the company's vice president, assured the Associated Press in 1998: "Elephants are one of the most beloved acts that performs in the circus today. Abusive techniques are absolutely prohibited."

Deborah Nelson is a Pulitzer Prize-winning investigative reporter as well as the director of the Carnegie Seminar of the Philip Merrill College of Journalism at the University of Maryland. Follow her on Twitter.